What is the meaning of "'arsah" in the noble Hadith?

Al-Arṣah is a wide-open space between houses, free of buildings, used for children's play. The intent of the ḥadīth is that the people of a neighborhood should not go to sleep full while their neighbor is hungry. Some scholars have deemed this ḥadīth weak, but it is supported by the ḥadīth: "He has not believed in me who goes to sleep full while his neighbor, next to him, is hungry, and he knows it."